Table 1

Co-stimulatory molecules and their ligands

Alveolar macrophagesT lymphocytes
CD40CD154 or CD40 ligand1-1
CD80 (B7.1)CD281-2 CTLA41-3
CD86 (B7.2)CD281-2 CTLA41-3

  • ↵1-1 Expressed upon T cell receptor (TcR) engagement by antigen (i.e. signal 1).

  • ↵1-2 Constitutively expressed.

  • ↵1-3 Expressed upon activation via signal 1, modulated via signal 2 (e.g. B7/CD28 dependent co-stimulation).